The invention relates to bag filter apparatus that is adapted to receive gas carrying a quantity of dust or other particulate matter whereby the dust is deposited on the surface of the filter apparatus while the carrier gas is permitted to pass therethrough. A bag filter apparatus usually comprises an assembly of gas previous filter bags supported by an apertured tube sheet and mounted directly on the outer surface of cylindrical wire frames or "cages" of transverse circular bands and longitudinal rods. The bags are assembled on the cages by a system of clamps, bands and tightening screws that are laboriously assembled and independently adjusted until they provide a predetermined spacing together with optimum collecting and cleaning efficiency. When a filter bag is to be repaired or replaced, each filter bag must be first disassembled and then removed. After it has been replaced it is adjusted to provide optimum filter effectiveness and maximum efficiency for removal of the collected dust particles from the filter wall.